Sewing machine



3 Sheets-Sheet l E.B.ALLEN SEWING MACHINE Filed May 3l, 1929 INVENTOR Erdman/'d 12A/Zelf lATTORNEY June 21, 1932.

E. BA ALLEN SEWING MACHINE June 21, 1932.

Filed May 31', 1929 3 sheets-sheer 2 NVENTOR Hwa/d /Zelz/ A TORNEY Filed May 3l, 1929 3 Sheets-Sheet 5 INVENTOR Edy/alzi iZe/e .j j f Another object of the invention is to pro- Patented `lune 2.1, 1932 Y UNITED STATES PATENT OFFICE'.y

- EDWARDB. ALLEN, NEWTOWN, coNNEorIcu'r VSEWING MACHINE Application filed May 31, 1929.v Serial No. 367,511.

. ide mechanism for adjusting acrank to vary its operative radius relative to its supporting shaft, such mechanism being operative without stopping the shaft. andV being of a` positive and preferably irreversible nature, so

hat the crank, for any position of adjustment, is positively held at the desired operative radius, from which it cannot move under centrifugal force or the forces of reaction to which the crank may be subjectedv at high operative speeds. Y j In the preferred embodiment of the invention there is provided a hollow shaft having at one end a head formed with ways in 'which a supporti-ng plate for the crank-pin Vis mounted to slide transversely of the shafts axis. Fitted within the shaft is a spindle having at one end an inclined portion fittingV an inclined sockety in the crank-supporting plate. The angle of inclination-is such that endwise movement of t-he spindle will easily shift the crank-supporting plate along its slideway but any forces applied t the crank will be but feebly transmitted, if at`al1,`to.

the spindle, the mechanism being practically irreversible. ,Y p t The invention is designed more particularly for embodiment in the needle-bar vibrating crank-mechanism of'ja buttonhole sewing machine, such as disclosed' in the pat'- ent to Allen, No. 1,629,139, of May 17, 19,27. I

of the gearing showninFig. V3.l Fig. is av top-plan view of the head ofthe shaft carrying the needle-bar-vibrating crank-mechanism. Fig. 6 is a section on the line 6.-.6, Fig.

5, with the crank-pin at oney extreme position of adjustment. Fig. 7 is a view similar to Fig. 6 but with the crank-pin at the other extreme position of adjustment. Fig. 8 is a bottom plan view of the crank-pin-supporting slide-,plate and a fragment of the supporting head carrying a stop-screw, and Fig. 9 is a disassembled perspective view ofthe parts shown in F igs, 5 to 8, inclusive.

vFor the purposes of the present disclosure the invention is described as embodied in an automatic straight buttonhole sewing machine constructed substantially in accordancek with the disclosure of the Allen Patent No. 1,629,139, and the patents referred to therein. The machine has the usual bed 1,k standard 2,' overhanging arm. 3 and head 4. The stitch-forming mechanism comprises the-reciprocating and laterally vibrating needlebar 5 carrying the eye-pointed needle 6. Thev needle-bar 5 is journaled in the swinging gate i' 7 which is mounted on pivot-pins 8 and derives its vibratory movement from the main sewing shaft 9. The gate 7 is connectedk by means of the link 10 tothe slotted arm 11 which is fulcrumed at 12 on ther bracket-arm 3 and is-connected by the link 13 to the crankpin 14 fixed to theradially movable lslideplate 1 '5 carried by the rotary guide-head 16l formed at the upper end of the hollow shaft 17 journaled vertically in the bracket-arm 3. l The guide-head 16 receives semi-rotational impulses through the train of gearsV 18 from the intermediate feed-actuating shaft 19 which carries the star-wheel 20-with which' mesh the pins 21 carried by they hub of the bevel-'geary 22 mounted onl the bearing pin 23 and' driven by the bevel-pinion 24 on the sewingshaft 9. VThe gear 22 is driven at half the speedof the 'shaft 9v and the gearing 18 is of such ratio that the guide-head 16 is-'given a Vhalf-rotation for each impulse of they star wheel 20 receivedfrom one of the pins 21.

The needlebar is reciprocated byv means of. the usual crank and link-connection 26 with thefsewing shaft 9.V l l VThe hollow shaft 17 has slidably fitted foo therein the vertical rod 27 having at its upper end the inclined portion 28 having dat, parallel and inclined, edge-faces 29 in sliding enga-gement with the similarly spaced parallel and inclined faces 30 provided by the plates 31, 32 mounted at the under side of the slide-block 15. The plate 31 is screwed fast in a fixed position to the slide-block. The plate 32 is secured to the slide-block by screws 83 which pass through enlarged holes34 inV the slide-block, giving clearance for a, limited adjustment of the plate 32 relative to the plate 31 under the influence of the adjusting screw 35. The adjustment is so made as to eliminate lost-motion between 'the inclined end 28 of the rod 27 and the plates 31, 82, while retaining a free yworking fit. It will be understood that endwise movement of the rod 27 will shift the slide-plate 15 and crankpin 14 diametrically of the guide-head 16 and vary the operative radius of the crankpin. The movement-of the slide-plate 15 is limitedinone direction by the stop-plate 36 which is fixed to one end of the slide-plate 15 in position Vto engage the flat edge-portion 37 of the guide-head. The movement of the slide-plate in the opposite direction is limited by the stop-screw 38 which is threaded into the guide-head 16 and held in adjusted position by the locking screw 89. The head of the stop-screw 38 is in position to be engaged by the stop-shoulder 40on the slide-plate. The angle of inclination of the end 28of the rod'y27 is preferably made small enough so that the motion is irreversible and that reactionary forces exerted on the crank-pin 14 will not shift the rod 27.

The rod 27 is formed at its lower end with a neck 41 embraced by the fork 42` at one `end of the pin 43 journaled in theboss 44 at the free end of the lever 45 fulcrumed at 46 on the standard 2. Adjustably secured to the lever 45 by a screw-and-slotconnectionf47 is the follower 48 which is periodically engaged `andlifted by the cam-plates 49 on the gear-wheel 50 fixed tov the vertical shaft 51 carrying the main feed-wheel 52 which is connected as usual to shift the work-clamp 53. In the presentmachine the cam-plates 49 are arranged to increase the amplitude of vibration of theneedle for barring both ends of a straight buttonhole; Y f

-Thespring 46 actsupon the lever 45 to hold Yit Vpressed upon the faces of the gearwheel 50 and cam-plates 49. The gear-wheel 50 on'the feed-wheel shaft 51 is driven from the shaft 19 through the train ofy gears 54. rlhe thickness of the cam-platesA 49 is such as to impart the desired increased amplitude of vibration to the needle-bar for barring the ends of a buttonhole and the stop 38 yis preferably adjusted tobe engaged by the shoulder 40v on the slide-block 15 when the camplates'49 are under the follower 48. Hence, 1n the particular machine illustrated,- means Myers copending application, Serial No.

272,416, iledfApril'24yl928.

By virtue of the present improvement higher Voperative machine speeds may be safely used without danger of displacement of parts of the needle-bar vibrating mechanism by centrifugal or reactionary forcest Having thus setforth the nature of the invention, what I claim herein is f 1.'In a sewing machine, a needle-bar, a vibratory needle-barfgate, a rotary crank and connections for vibrating said gate, means for imparting operative impulses to said crank, f means for changing the operative radius of said crank while the machine is in operation, andV means for positively retaining said crank against displacement from its adjusted position. Y

2. In a sewing machine, a needle-bar, a vibratory needle-bar gate, a rotary hollow crank-shaft having. a guide-head, a crankpin slidably mounted on said guide-head, an operative connection between said-crank-pin and fneedle-bar' gate, a rod disposed within said hollow shaft and having an inclined end with parallel operative face-elements, spaced follower-elements rigid with said crank-pin and engaging' the` inclined operative faceelements of said rod, and means vfor shifting said. rod endwise without stopping the machine. Y

y3. Inca sewing machine, a needle-bar, a vibratory needle-bar gate, a rotary hollow crank-shaft,a crank-pin carriedby and movable "laterally of the axis 'of said crank-shaft, an operative connection between said crankpin and needle-bar gate, anendwise movable rod disposed within said hollow crank-shaft and rreversibly and positively connected to move said crank-pin in Vopposite directions laterally of the` axis of said crank-shaft, and means for moving said rod endwise without stopping the machine. v

-4. In a sewing machine, a needle-bar, a vibratory needle-bar gate, a crank-shaft and means for imparting. thereto semi-rotational impulses, a crank on said shaft, an operative connection between said crank and needle-bar gate, and means for` changing the operative radius of said crank,said means including an endwise movable rod having spaced inclined operative face-elements, and follower means connected to said crank and in simultaneous working engagement with said in= clined face-elementen Y I v f 4 1 5. In `asewing machine, stitch-forming mechanism, work-shifting mechanism, a main-shaft connected to drive said mechanisms, a shaft having a guide-head, a slide mounted in said guide-head and having fixed and adjustable spaced follower-elements, a crank carried by said slide and connected t0 impart relative stitch-positioning movements to one of said mechanisms, an adjusting rod movable endwise of said shaft and having spaced operative face-elements in engagement with said follower-elements, and means for shifting said rod in opposite directions without stopping the stitch-forming mechanism.

6. In a sewing machine', stitch-forming mechanism, work-shifting mechanism, a main-shaft, a crank-shaft connected to be driven by said main-shaft, a crank adjustably mounted on said crank-shaft and connected to impart relative stitch-positioning movements to one of said mechanisms, a crankadjusting element, and an irreversible connection between said crank-adjusting element and said crank operative to positively move said crank toward or away from the axis of said crank-shaft without stopping the stitchforming mechanism.

In testimony whereof, I have signed my name to this specification.

EDWARD B. ALLEN.

CERTlFIGATE 0F CORRECTION.

Patent No. 1,864,165. June 21, 1932.

EDWARD B. ALLEN.

it is hereby certified that the above numbered patent was erroneously issued to the inventor said "Allen", whereas said patent should have been issued to The Singer Manufacturing Company, of Elizabeth, New Jersey, a corporation of New Jersey, as assignee ot the entire interest in said invention, as shown by the records of assignments in this office; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 4th day of October, A. D. 1932.

M. J. Moore, (Seal) Acting Commissioner of Patents. 

